The present invention generally relates to the field of loading docks, and more specifically to a vehicle shelter for a loading dock that is positioned around a loading dock opening to provide a weather-tight barrier between the loading dock and the open end of a vehicle (e.g., a truck or trailer).
Most warehouses, manufacturing facilities, and large retail stores include loading docks that provide a location for loading and unloading vehicles. Loading docks typically include a raised platform and a dock opening positioned above the raised platform. A dock wall, having two vertical side portions extending upwardly from the platform and a horizontal upper portion connecting the tops of the side portions, forms the dock opening. Vehicles can back toward the dock opening until the back of the vehicle is abutting the platform. The platform sometimes includes a dockleveler that provides a ramp between the platform and the bed of the vehicle to facilitate loading and unloading of the vehicle (e.g., by a forklift).
Many loading docks include dock seals and shelters that provide a barrier between the dock wall and the back of the vehicle. Historically, there have been two types of dock shelters.
The first type of dock shelter includes a rigid frame made of wood or welded steel tubing. The rigid frame is usually made up of a head frame that is positioned above the dock opening and side frames that are positioned on opposing sides of the dock opening. Fiberglass panels or flexible fabric covers the outer sides of the frame in order to establish a weather-tight barrier.
The second type of dock shelter includes a flexible frame, which inhibits damage to the shelter in the event that a vehicle backs into the shelter. The flexible frame typically includes a pair of side frames that are secured to each side of the dock opening. Each side frame includes a back support (e.g., wood or steel tubing) that is mounted to the dock wall. The back support is connected to a front support (e.g., wood or steel tubing) by a lateral support. The lateral support (commonly steel tube) is pivotally connected to both of the front and back supports such that the front support is able to move relative to the back support. Flexible fabric extends between the top ends and outer sides of the front and back supports in order to provide a weather-tight barrier around the outer surface of the vehicle shelter. The fabric is sized to prevent the front support from pivoting (i.e., falling) downward. The fabric is therefore under tension during normal use. When a vehicle backs into the dock shelter off center and impacts one of the side frames, the front support moves upward and toward the back support because the lateral supports pivot with respect to the front and back supports preventing damage to the shelter. After the vehicle moves away from the loading dock, the dock shelter returns to its normal position with the fabric placed under tension.
The front of both flexible and rigid frames commonly includes a head curtain and side curtains with flexible stays mounted therein. The head and side curtains contact the top and sides of the vehicle, respectively, to provide a barrier between the inside of the loading dock and the exterior environment.
The above-described frames and corresponding shelters provide good protection against the elements. However, as with most loading dock equipment, simplified construction techniques and improved structural stability are desirable design goals. In addition, the shelter must withstand repeated uses under a variety of weather and loading conditions.
The present invention provides a vehicle shelter for a loading dock. The vehicle shelter includes a flexible frame, flexible cover and a curtain. The curtain and flexible cover are each coupled to the flexible frame. The flexible frame includes supports that are made up of pairs of channels that have an open cross-section. The channels are secured together by clinching, screwing, riveting or any well known technique to form supports.
The channels are preferably made from light gauge steel (e.g., 16 GA) which has several advantages over a more conventional heavy gauge rectangular tubing. First, self-drilling screws easily pierce light gauge steel thereby facilitating attachment of curtains and trim angles to the faces of the supports and making it easier to drill mounting holes through the faces of the supports in order to attach the supports to the loading dock wall. Second, using light gauge steel makes the dock shelter easier to assemble because the supports weigh less. Finally, using light gauge steel allows brackets to be clinched to a single channel before two channels are joined together to form a support.
It has also been found that the design of the present invention provides significant advantages over the use of wood in that wood may warp, twist, and split. The present invention is also resistant to rotting and insect damage.
More specifically, the flexible frame of the vehicle shelter includes a pair of side frames. Each side frame includes a back support adapted to be mounted to a loading dock wall, and a front support that is pivotally connected to the back support. The front and back supports are formed from a pair of open channels. In a preferred form, the pairs of channels that form the supports are C-shaped.
In another form, a lateral support extends from the back support to the front support and is pivotally connected to both the front and back supports. The pivotal connection between the lateral support and the front and back supports allows the front support to move relative to the back support when a vehicle comes into contact with the side frame of the shelter as the vehicle enters the loading dock off center.
In another form, the flexible frame further includes a top support coupled to a portion of the front supports in each side frame in order to support a top cover. In this form, a head curtain can be secured to the front face of the top support.
The present invention also provides an improved method of making a vehicle shelter for a loading dock and mounting the vehicle shelter to a loading dock wall. The method comprises the steps of forming (e.g., rolling on a roll-forming machine) sheet metal into channels that have an open cross-section, joining (e.g., clinching) pairs of the channels together to form supports, mounting back supports to a loading dock wall, and pivotally connecting front supports to each of the back supports to form side frames.
In a preferred form of the method, the step of pivotally connecting the front supports to the back supports is done by pivotally connecting a lateral support to both of the front and back supports. The lateral supports may be a steel tube or formed from a pair of C-shaped channels that are clinched together.